Medicare Part D Spending Caps Associated With Increased Medication Usage
Key Takeaways:
- After the Inflation Reduction Act (IRA) capped Medicare Part D out-of-pocket costs, rates of medication prescriptions increased at higher rates compared to commercial insurance.
- When compared with commercial insurance, average rates of medication utilization among Medicare Part D beneficiaries were 4.1% higher for low-cost drugs, 20.7% higher for medium-cost drugs, 23.1% higher for high-cost drugs, and 35.9% higher for very high-cost drugs.
- The findings demonstrate significant improvements in drug access, espcially among higher-cost medications, which could potentially improve patient health outcomes.
Over 57 million US adults receive coverage for prescription medications through Medicare Part D, but the plan’s high cost-sharing requirements have resulted in substantial out-of-pocket spending for patients.
In 2022, Congress passed the IRA, which capped annual out-of-pocket costs at $3300. The cap was lowered to $2000 in 2025.
Study Methods and Outcomes
Researchers conducted a study to assess the impact of this policy change on medication utilization among patients with Medicare. Using data from the Symphony Health Metys database, investigators compared the quarterly prescription fills for Medicare and commercial medications from 2022 to 2025.
Medications were categorized based on monthly costs: low (less than $100), medium ($100-$829), high ($830-$6999), and very high (over $7000).
The study included 3053 medications, accounting for 92.9% of gross Medicare Part D spending in 2023. Among these prescription drugs, 1534 (50.2%) were low cost, 882 (28.9%) were medium cost, 455 (14.9%) were high cost, and 182 (6.0%) were very high cost.
Capped Out-of-Pocket Costs Increased Medication Prescriptions and Utilization
The use of low-cost prescription medications decreased slightly from 2022 to 2025. Medicare prescriptions decreased from 67 976 to 66 979, and commercial insurance prescriptions decreased from 32 902 to 30 691.
Rates of usage among higher-cost drugs increased among Medicare beneficiaries compared to those with commercial insurance. Medium-cost drug increased from 21 742 to 28 512 with Medicare and from 6740 to 8769 with commercial insurance.
High-cost medications increased slightly from 705 to 973 with Medicare and had no noteworthy difference with commercial insurance.
Very high-cost prescriptions increased significantly from 830 to 1229 with Medicare while commercial prescriptions decreased from 352 to 302.
The use of Medicare drugs increased over time, and by the end of the study, the average difference in medication utilization between Medicare beneficiaries and those with commercial insurance was 4.1% for low-cost drugs, 20.7% for medium-cost drugs, 23.1% for high-cost drugs, and 35.9% for very high-cost drugs.
Implications for Managed Care
The study indicated that spending caps are associated with increased utilization of prescription medications. While the caps indicate significant improvements in access, their impact on clinical health outcomes has yet to be seen and should be the focus of future studies.
The authors said, “These results suggest that the policy may have substantially improved patients’ access to high-cost medications, and the magnitude of these changes has important implications for future policies to address Medicare Part D spending by patients and the government.”
Reference
Cai CL, Anderson KE, Kesselheim AS, Rome BN. Changes in medication use after Medicare part D annual out-of-pocket spending caps. JAMA Health Forum. 2026;7(6):e261545. doi:10.1001/jamahealthforum.2026.1545
